218 research outputs found
Kinematics and H_2 morphology of the multipolar Post-AGB star IRAS 16594-4656
context: The spectrum of IRAS 16594-4656 shows shock excited H_2 emission and
collisionally excited emission lines such as[O I],[C I],and [Fe II]. aim: The
goal is to determine the location of the H_2 and [Fe II] shock emission, to
determine the shock velocities,and constrain the physical properties in the
shock. methods: High resolution spectra of the H_2 1-0 S(1),H_2 2-1 S(1), [Fe
II], and Pa emission lines were obtained with the near infrared
spectrograph Phoenix on Gemini South. results: The position-velocity diagrams
of H_2 1-0 S(1), H_2 2-1 S(1), and [Fe II] are presented. The H_2 and [Fe II]
emission is spatially extended. The collisionally excited [O I] and [C I]
optical emission lines have a similar double peaked profile compared to the
extracted H_2 profile and appear to be produced in the same shock. They all
indicate an expansion velocity of ~8 km/s and the presence of a neutral, very
high density region with about 3 x 10^6 to 5 x10^7 cm. The
[Fe II] emission however is single peaked. It has a gaussian FWHM of 30 km/s
and a total width of 62 km/s at 1% of the peak. The Pa profile is even
wider with a gaussian FWHM of 48 km/s and a total width of 75 km/s at 1% of the
peak. conclusions: The H emission is excited in a slow 5 to 20 km/s shock
into dense material at the edge of the lobes, caused by the interaction of the
AGB ejecta and the post-AGB wind. The 3D representation of the H_2 data shows a
hollow structure with less H_2 emission in the equatorial region. The [Fe II]
emission is not present in the lobes, but originates close to the central star
in fast shocks in the post-AGB wind or in a disk. The Pa emission also
appears to originate close to the star.Comment: 11 pages and 8 figures; A&A in press; the paper includig high
resolution figures can be downloaded from
http://homepage.oma.be/gsteene/publications.htm
In vivo silencing of alpha-synuclein using naked siRNA
<p>Abstract</p> <p>Background</p> <p>Overexpression of α-synuclein (SNCA) in families with multiplication mutations causes parkinsonism and subsequent dementia, characterized by diffuse Lewy Body disease <it>post-mortem</it>. Genetic variability in <it>SNCA </it>contributes to risk of idiopathic Parkinson's disease (PD), possibly as a result of overexpression. <it>SNCA </it>downregulation is therefore a valid therapeutic target for PD.</p> <p>Results</p> <p>We have identified human and murine-specific siRNA molecules which reduce <it>SNCA in vitro</it>. As a proof of concept, we demonstrate that direct infusion of chemically modified (naked), murine-specific siRNA into the hippocampus significantly reduces <it>SNCA </it>levels. Reduction of <it>SNCA </it>in the hippocampus and cortex persists for a minimum of 1 week post-infusion with recovery nearing control levels by 3 weeks post-infusion.</p> <p>Conclusion</p> <p>We have developed naked gene-specific siRNAs that silence expression of <it>SNCA in vivo</it>. This approach may prove beneficial toward our understanding of the endogenous functional equilibrium of <it>SNCA</it>, its role in disease, and eventually as a therapeutic strategy for α-synucleinopathies resulting from <it>SNCA </it>overexpression.</p
An exploratory study to assess the activity of the acarine growth inhibitor, fluazuron, against Sarcoptes scabei infestation in pigs
Background: The most common treatments for scabies in human and veterinary settings are topical 5% permethrin or systemic treatment with ivermectin. However, these treatments have very little activity against arthropod eggs, and therefore repeated treatment is frequently required. In-vitro, biochemical and molecular studies have demonstrated that human mites are becoming increasingly resistant to both acaricides. To identify alternate acaricides, we undertook a pilot study of the in vivo activity of the benzoylphenyl urea inhibitor of chitin synthesis, fluazuron, in pigs with sarcoptic mange. Findings. Pigs (n = 5) were infested with S. scabei var suis, and randomised to treatment at the start of peak infestation with fluazuron at a dose of 10 mg/kg/day per os for 7 days (n = 3) or no treatment (n = 2). Clinical scores, skin scrapings for mite counts and blood sampling for pharmacokinetic analysis were undertaken. Fluazuron was well absorbed in treated pigs with measureable blood levels up to 4 weeks post treatment. No adverse effects were observed. Modest acaricidal activity of the compound was observed, with a reduction in severity of skin lesions in treated pigs, as well as a reduction in number of scabies mite's early life stages. Conclusions: The moderate efficacy of fluazuron against scabies mites indicates a lead to the development of alternate treatments for scabies, such as combination therapies that maybe applicable for human use in the future
Viewing Cognitive Conflicts as Dilemmas: Implications for Mental Health
The idea that internal conflicts play a significant role in mental health has been extensively addressed in various psychological traditions, including personal construct theory. In the context of the latter, several measures of conflict have been operationalized using the Repertory Grid Technique (RGT). All of them capture the notion that change, although desirable from the viewpoint of a given set of constructs, becomes undesirable from the perspective of other constructs. The goal of this study is to explore the presence of cognitive conflicts in a clinical sample (n = 284) and compare it to a control sample (n = 322). It is also meant to clarify which among the different types of conflict studied provides a greater clinical value and to investigate its relationship to symptom severity (SCL-90-R). Of the types of cognitive conflict studied, implicative dilemmas were the only ones to discriminate between clinical and nonclinical samples. These dilemmas were found in 34% of the nonclinical sample and in 53% of the clinical sample. Participants with implicative dilemmas showed higher symptom severity, and those from the clinical sample displayed a higher frequency of dilemmas than those from the nonclinical sample
How are social identities linked to self-conception and intergroup orientation? The moderating effect of implicit theories
Social identity approaches assume that social identification affects both self-conception and intergroup orientation. The authors contend that such social identification effects are accentuated when people hold a fixed view of human character and attribute immutable dispositions to social groups. To these individuals, social identities are immutable, concrete entities capable of guiding self-conception and intergroup orientation. Social identification effects are attenuated when people hold a malleable view of human character and thus do not view social identities as fixed, concrete entities. The authors tested and found support for this contention in three studies that were conducted in the context of the Hong Kong 1997 political transition, and discussed the findings in terms of their implications for self-conceptions and the meaning of social identification
Low exposure long-baseline neutrino oscillation sensitivity of the DUNE experiment
The Deep Underground Neutrino Experiment (DUNE) will produce world-leading
neutrino oscillation measurements over the lifetime of the experiment. In this
work, we explore DUNE's sensitivity to observe charge-parity violation (CPV) in
the neutrino sector, and to resolve the mass ordering, for exposures of up to
100 kiloton-megawatt-years (kt-MW-yr). The analysis includes detailed
uncertainties on the flux prediction, the neutrino interaction model, and
detector effects. We demonstrate that DUNE will be able to unambiguously
resolve the neutrino mass ordering at a 3 (5) level, with a 66
(100) kt-MW-yr far detector exposure, and has the ability to make strong
statements at significantly shorter exposures depending on the true value of
other oscillation parameters. We also show that DUNE has the potential to make
a robust measurement of CPV at a 3 level with a 100 kt-MW-yr exposure
for the maximally CP-violating values \delta_{\rm CP}} = \pm\pi/2.
Additionally, the dependence of DUNE's sensitivity on the exposure taken in
neutrino-enhanced and antineutrino-enhanced running is discussed. An equal
fraction of exposure taken in each beam mode is found to be close to optimal
when considered over the entire space of interest
A Gaseous Argon-Based Near Detector to Enhance the Physics Capabilities of DUNE
This document presents the concept and physics case for a magnetized gaseous argon-based detector system (ND-GAr) for the Deep Underground Neutrino Experiment (DUNE) Near Detector. This detector system is required in order for DUNE to reach its full physics potential in the measurement of CP violation and in delivering precision measurements of oscillation parameters. In addition to its critical role in the long-baseline oscillation program, ND-GAr will extend the overall physics program of DUNE. The LBNF high-intensity proton beam will provide a large flux of neutrinos that is sampled by ND-GAr, enabling DUNE to discover new particles and search for new interactions and symmetries beyond those predicted in the Standard Model
Snowmass Neutrino Frontier: DUNE Physics Summary
The Deep Underground Neutrino Experiment (DUNE) is a next-generation long-baseline neutrino oscillation experiment with a primary physics goal of observing neutrino and antineutrino oscillation patterns to precisely measure the parameters governing long-baseline neutrino oscillation in a single experiment, and to test the three-flavor paradigm. DUNE's design has been developed by a large, international collaboration of scientists and engineers to have unique capability to measure neutrino oscillation as a function of energy in a broadband beam, to resolve degeneracy among oscillation parameters, and to control systematic uncertainty using the exquisite imaging capability of massive LArTPC far detector modules and an argon-based near detector. DUNE's neutrino oscillation measurements will unambiguously resolve the neutrino mass ordering and provide the sensitivity to discover CP violation in neutrinos for a wide range of possible values of ÎŽCP. DUNE is also uniquely sensitive to electron neutrinos from a galactic supernova burst, and to a broad range of physics beyond the Standard Model (BSM), including nucleon decays. DUNE is anticipated to begin collecting physics data with Phase I, an initial experiment configuration consisting of two far detector modules and a minimal suite of near detector components, with a 1.2 MW proton beam. To realize its extensive, world-leading physics potential requires the full scope of DUNE be completed in Phase II. The three Phase II upgrades are all necessary to achieve DUNE's physics goals: (1) addition of far detector modules three and four for a total FD fiducial mass of at least 40 kt, (2) upgrade of the proton beam power from 1.2 MW to 2.4 MW, and (3) replacement of the near detector's temporary muon spectrometer with a magnetized, high-pressure gaseous argon TPC and calorimeter
Snowmass Neutrino Frontier: DUNE Physics Summary
The Deep Underground Neutrino Experiment (DUNE) is a next-generation
long-baseline neutrino oscillation experiment with a primary physics goal of
observing neutrino and antineutrino oscillation patterns to precisely measure
the parameters governing long-baseline neutrino oscillation in a single
experiment, and to test the three-flavor paradigm. DUNE's design has been
developed by a large, international collaboration of scientists and engineers
to have unique capability to measure neutrino oscillation as a function of
energy in a broadband beam, to resolve degeneracy among oscillation parameters,
and to control systematic uncertainty using the exquisite imaging capability of
massive LArTPC far detector modules and an argon-based near detector. DUNE's
neutrino oscillation measurements will unambiguously resolve the neutrino mass
ordering and provide the sensitivity to discover CP violation in neutrinos for
a wide range of possible values of . DUNE is also uniquely
sensitive to electron neutrinos from a galactic supernova burst, and to a broad
range of physics beyond the Standard Model (BSM), including nucleon decays.
DUNE is anticipated to begin collecting physics data with Phase I, an initial
experiment configuration consisting of two far detector modules and a minimal
suite of near detector components, with a 1.2 MW proton beam. To realize its
extensive, world-leading physics potential requires the full scope of DUNE be
completed in Phase II. The three Phase II upgrades are all necessary to achieve
DUNE's physics goals: (1) addition of far detector modules three and four for a
total FD fiducial mass of at least 40 kt, (2) upgrade of the proton beam power
from 1.2 MW to 2.4 MW, and (3) replacement of the near detector's temporary
muon spectrometer with a magnetized, high-pressure gaseous argon TPC and
calorimeter.Comment: Contribution to Snowmass 202
A Gaseous Argon-Based Near Detector to Enhance the Physics Capabilities of DUNE
This document presents the concept and physics case for a magnetized gaseous
argon-based detector system (ND-GAr) for the Deep Underground Neutrino
Experiment (DUNE) Near Detector. This detector system is required in order for
DUNE to reach its full physics potential in the measurement of CP violation and
in delivering precision measurements of oscillation parameters. In addition to
its critical role in the long-baseline oscillation program, ND-GAr will extend
the overall physics program of DUNE. The LBNF high-intensity proton beam will
provide a large flux of neutrinos that is sampled by ND-GAr, enabling DUNE to
discover new particles and search for new interactions and symmetries beyond
those predicted in the Standard Model.Comment: Contribution to Snowmass 202
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